Projectile



H. H. MoHAuP-r 2,1,14 i

PoJEcTILE Filed Oct. 3, 1941 Innfar:

l A fvwm: ys,

Wharf@ l MHH 0 .MKWMW awr m f, 9 7, si 4 4 l W. 5 o we. w s n l Pw a n M K/f i x/ VMM\Y\\\\ PROJECTILE Henry Mohaupt, Washington, D. C.,

or to Sageb,

assign- Societe Anonyme de Gestion et dExploitation de Brevets, Fribourg, Switzerland, a corporation of Switzerland Application October 3, 1941, Serial No. 413,549

7 claims. l

This invention relates to improvements in projectiles which include collapsible secondary projectiles cf the type set out in my copending applications Serial No. 354,752, led August 29, 1940; Serial No. 378,297, filed February 10, 1941; and Serial No. 388,141, led April 11, 1941.

One of the features of the present invention is the provision of a projectile adapted for firing from a cannon and having a velocity of the order of 80o or 900 feet per second or higher, and including a ballistic nose or cap for reducing air resistance and for assuring the collapsing and expulsion of the secondary projectile within a predetermined range of distance upon the impact against the target.

A further feature of the invention is the provision of a projectile in which a secondary projectile is securely held in position during normal transport and up until the time of detonation of the charge which is employed for collapsing the same, in a, construction which permits a direct and easy assembly of the elements.

Another feature of the invention is the provision of a projectile including a body and a ballistic cap, with means for causing the ballistic cap to be deformed in a predetermined fashion, so that no deilective distortional materials may be presented in the path of the expelled secondary projectile.

A further feature of the invention is the provision of a projectile having a body section and a front section, this front section having a hollow ballistic nose or cap and also having a. thickened rearward portion for engagement with the body and cooperative with the body for securing the secondary projectile in a maintained position, and in which preferably this thickened portion is provided by an intermediate member separate from the thin, light cgive which provides the ballistic nose or cap, this intermediate member having its external and internal walls convergent forwardly relative to its axis, so that it provides a guide for causing an expanding outward movement of the cap when the same is driven relatively backward at impact, and also a guide for the secondary projectile during the collapsing and expulsion thereof.

primarily intended and illustrated as employed with a projective apparatus such as a rided cannon, it will be understood that the structure can be otherwise employed in projectile fashion, as a bomb for dropping from aircraft, for rlng from smooth bore mortars, etc.

With these and other features as objects in view, as will appear in the course of the following specification and claims, an illustrative form of practicing the invention is set out on the alccompanying drawings, in which:

Figure 1 is an axial sectional view through one -l type of construction.

Figures 2, 3 and 4 are fragmentary views each showing a part of modified types of construction.

A body section of the projectile is comprised of a strong body lll having an internal cavity for receiving an explosive charge H. This explosive charge is preferably provided with a conical cavity of predetermined shape and size at its forward end. The body l0 is illustratively provided with driving means shown as a driving band I2 and has a screw threaded plug I3 at its base into which may be threaded the connection I4 of a base fuse I5 which has a housing portion I6 containing an inertia body l1 normally held in rearward position by a spring I8 and serving for pivotally supporting the centrifugally-actuated safety ring pin assembly I9 having the lring pin F. A jacket 20 of the fuse assembly contains a booster charge 2| of pressed explosive and has a. primer P in its rear wall for engagement by the firing pin. The front end of jacket 20 is closed by a threaded booster detent plate 22 which serves in protecting the fuse charge during handling and storage of the fuse and projectile, and insures a maximum booster action. This fuse is shown as an illustrative example of an appropriate fuse which has the requisite characteristic of detonating and effecting detonation of an eX- plosive charge in the shortest possible time-after impact and with substantial uniformity in the time interval from the initial detonation of the primer until the main charge has become a gas.

A secondary projectile 25 having the general form of a hollow cone is illustrated as positioned directly upon the explosive charge H, this charge being so formed and dimensioned, as by casting in position, that there is contact between the charge and the external wall of the cone for at least part of the area of the latter, to assure the charge against movement.

The forward end of the body l0 has an internal shoulder 3l! and screw threads 3|.

The front section for the projectile is illustrated in Fig. 1 as comprised of an intermediate member 35 and a 'ballistic nose or cap 36 illustrated as being a light ogive which is less resistant to crushing than the body and is illustrated as of substantially uniform thickness, and may be of steel thinner than the steel section of the body for example. It should be at least 3 millimeters thick for safety against deformation during manufacture and handling; and may be of steel of 7 to 10 millimeters thickness for a 75 millimeter projectile, with a corresponding increase or decrease of thickness for larger or smaller calibers. The intermediate member 35 has its rearward end threaded for connection with the body at the threads 3| thereof, and includes a radially outwardly extending flange 31 of substantially the same diameter as the caliber of the body I and seated on the forward end thereof to provide a tight joint, a packing gasket 38 being interposed if desired. Forwardly of the flange 31, the intermediate member 35 has its outer surface 42 formed to converge forwardly and to fit tightly against the internal wall of the ballistic nose or cap 36. This nose or cap 36 is secured to the intermediate member 35 by suitable means such as a weld 39 adjacent the ange 31. Internally, the intermediate member 35 is hollow and has its internal wall 4|! convergent forwardly, illustratively at an angle of about 2 degrees to the axis, and having a curvature inwardly at an angle increasing from this. This intermediate member 35 provides a thickened portion for the front section, so that it can serve as a guide for the secondary projectile while it is being collapsed and expelled. The rearward end of the internal wall 40 is preferably chamfered to provide a conical surface M having an angle of about 45 degrees.

The secondary projectile 25 is engaged between the body l0 and the intermediate member 35, the construction in the illustrative form of Fig. 1 including a radially projecting flange 45 on the conical member which rests against the shoulder 30 and is pressed thereagainst by the rearward end of the intermediate member 35. The secondary projectile 25 is thus assured against axial and rotative movement relative to the body. The chamfered surface 4| is preferably so devised that its rearward edge lies substantially in the cylindrical surface of prolongation of the internal wall of the body I0.

The ballistic nose or cap 36 provides a streamlining for the projectile and is illustrated as having a small flattened front end 50.

In construction, the secondary projectile 25, illustratively shown as a full cone, is preferably of metal of substantially uniform thickness and having an apex half-angle (i. e., the angle between a generatrix and the axis) of substantially 21 degrees. This angle should be between 18 and 30 degrees. The length of the front section for a projectile having a muzzle velocity of around 800 to 1000 feet per second should be of the order of twice the caliber of the projectile, and it has likewise a length which is substantially twice the caliber of the secondary projectile 25. The length of the guide wall 40 provided by the intermediate member is preferably from one-third to threefourths the length of the secondary projectile 25. The thickened portion of the front section, illustratively presented by the intermediate member 35, should preferably comprise about one-third of the distance from the front end of the secondary projectile to the apex end 5|] of the nose or cap.

The cone may be constructed of various materials, but preferably is of a mild carbon steel such as cold-rolled steel, as this metal has an adequate structural strength at desirable proportions of wall thickness and mass; it has a high melting point so that the secondary projectile remains essentially integral under the heat and pressure of detonation; it is ductile so that it deforms uniformly under the initial gas pressures devel- 4 Oping; and it is of a specific gravity which assures a high effect for the weight and mass employed. It is preferred to have a cone of substantially uniform wall thickness, which desirably may be about 1.9 millimeters for a 75 millimeter projectile caliber and from around 2 to 3 millimeters for a 105 millimeter projectile caliber. This cone may, however, be thicker at the apex than at the free edge, or vice versa, depending somewhat upon the type and distribution of the main charge Il. A thin apex is useful with a low apex angle, as presenting more metal at the base end of the cone.

The assembled projectile can be transported and handled without shifting of its parts, as the secondary projectile 25 is maintained fixedly in position by being clamped between the end shoulder on the body l0 and the intermediate member 35, and this secondary projectile 25 itself holds the charge il against movement. When the projectile is discharged from a cannon, likewise, these parts cannot shift or rotate with respect to one another, and hence the parts remain in the accurately predetermined position until the moment of impact.

Upon impact of the apex end upon the target, the material of the ogive is forced relatively backwardly while the body I0 and the intermediate member 35 continue forward. This crushing effect appears partly as a yielding adjacent the apex end 50, but largely as a spreading or expanding or flaring of the larger diameter of the skirt wall, being guided by the tapered outer surface of the intermediate member 35, so that the ballistic cap or nose, as a whole, moves relatively backward upon the other parts of the projectile, without crushing or deformation which might interpose irregularly defiective masses of metal into the prospective path of the secondary projectile, and has the effect of providing a cushion or shock absorbing member for preventing the explosive charge being irregularly detonated by the concussion at impact. The light welding connection 39 is easily broken, and

45 does not essentially hinder this effect, but interposes an initial resistance to the spreading or flaring, at the moment of impact, so that, by momentum of the inertia member I9, a heavy immediate blow is delivered along the length of o the firing pin F to produce ignition and detonation in the fuse. In practice, this fuse and the associated explosive charge are designed and constructed for instantaneous detonation, and this detonation'of the entire charge Il should be 5 completed in a time interval of the order of a the secondary projectile 25 radially into a mass of small diameter located in the line of the axis of the body, and to expel it forwardly, the internal wall 40 serving as a guide for initially shaping the secondary projectile and for guiding the blast of escaping gas, so that the inward pressures are maintained until the secondary projectile has been collapsed into a pencil-like form. This collapsing occurs rapidly, so that this pencil-like form is attained within a distance corresponding to a forward movement of the secondary projectile oi one or two times the original altitude of the cone. .The escaping gases may further serve to distend the thin material of the ballistic nose or cap, so that this thin pencil-like secondary projectile is delivered accurately in direction. and impacts upon the target as a mass of metal which has been expelled at a velocity which is many times the velocity of the projectile itself at the moment of .impact and may, for example, be as high as 18,000 or more feet per second. Due to the small cross-section of the collapsed secondary projectile and its high velocity, it is capable of penetrating considerable thicknesses of armor and like target material; and due to the conditions of heat and pressure, it appears as though it melts its way through armor and delivers a mass of highly heated metal beyond the armor.

In the modified form shown in Fig. 2, the body Illa has an external chamfered surface 42a to receive the thin ogive 36, which likewise may be secured in position by appropriate means such as the illustrated screw threads 35a. The intermediate member 35a is shortened, so that it fits within the body lila; and is formed with a beveled rear surface M a to engage the correspondinglyformed free edge on the secondary projectile 25, and cooperates with the body for supporting the secondary projectile in xed position and for serving as a guide during the collapsing and explosion. With this structure, the ogive is flared upon impact by the spreading action of the body surface Ma.

In the modified form shown in Fig. 3, the body lub has the external chamfered surface 42a to receive the thin ogive 36 and has an internal groove Mb. The secondary projectile Z5 is pressed into the body with a tight fit: it may have a cylindrical portion 25a as shown in the dotted line intermediate position, for tightly tting the internal wall of the body I b. When the projectile 25 has been tted upon the charge, a groove 25h may be formed therein by an internal rolling operation to engage the cone in the groove Mb so that it is iixedly secured in location. In this form, the ogive 36 is illustrated as secured to the body by externally rolling a groove into its edge, so that the material is forced into a groove 42h provided in the surface Illa.

In the modied form shown in Fig. 4, the body itc externally h'as the flare-eiective wall surface Ma, and internally has the groove llc and the beveled shoulder 30a. The secondary projectile 251s pressed against the shoulder 30a, with av tight lit within the body; and then a securing member Mb, shown as a split ring, is pressed'into the body so that it snaps into the groove Mc and engages the free edge of the projectile 25. In this form, it is preferred to shape the free end of th'e hollow conical projectile V:i to have the cylindrical external surface to fit the inner wall of the body, so that this cylindrical surface and the conical external surface assure a correct positioning of coaxiality. In this form, further. the ogive 36 is illustrated as held in position by a rolled groove, corresponding to that shown in Fig. 3, but with the additional employment of a solid spring metal ring 42e which is pressed down along the ogive wall until it snaps into th'e groove formed by the rolling operation, the shaping of the parts preferably being devised to provide as smooth a surface as feasible. Y

It is obvious that the invention is not limited solely tothe form of construction shown, but that it may be practiced in many ways within the scope of the appended claims.

I claim:

1. A projectile comprising a strong body having an explosive charge therein of high explosion velocity, a strong intermediate member secured to said body and having an external forwardly convergent surface, a h'ollow ballistic nose tting said convergent surface and welded to said intermediate member whereby a smooth external surface is provided and said nose is caused to are at its rear end upon impact of the projectile, a secondary projectile having the general form of a hollow cone with its base toward the front end of the projectile and provided with an external peripheral projection engaged between said body and intermediate member whereby the cone is accurately maintained vin position, and means for detonating the charge instantaneously upon impact of the projectile for effecting radial collapsing and expulsion of the secondary projectile.

2. A projectile comprising a body having an explosive charge therein of high' explosion velocity, a ballistic nose, an intermediate member secured to said body and to `said ballistic nose, a secondary projectile having the general form of a. hollow cone with its base toward the front end of the projectile and provided with an external peripheral ange engaged between said body and intermediate member whereby the cone is accurately maintained in position, and means for detonating the charge instantaneously upon impact of the projectile for effecting radial collapsing and forward expulsion of the secondary projectile, said intermediate member having at least part of its internal surface with a forwardly convergent taper for guiding said cone during the initial collapsing.

3. A projectile comprising a h'ollow body section and a hollow front section, said body section having an explosive charge therein of high explosion velocity, said front section including a hollow ballistic nose and a radially thickened annular portion at its rearward end and being connected to the front end of said body section, the connected sections having at their juncture a cavity extending outwardly from the internal hollow, a, secondary projectile located at the front of the explosive charge and having the general form of a hollow cone with its base directed forwardly and h'aving an edge portion fitting into said cavity whereby the secondary projectile is assured against movement prior to the detonatlon, said secondary projectile being constructed and arranged to be collapsed in diameter and expelled forwardly by detonation gases from said explosive charge, the internal wall of the thickened annular portion including a tapered internal surface constituting a guide for the secondary projectile dur ing its initial forward movement upon the detonation, and means for instantaneously ring the charge upon impact of the projectile with the target, said hollow front section and its connection with the body section being constructed and arranged for eifecting the actuation of said ring means upon impact and for maintaining a free space forwardly of the front edge of the body section during the collapsing and expulsion of the secondary projectile.

4. A projectile comprising a hollow body section and a hollow front section, said body section having an explosive charge therein of high explosion velocity, said charge having a conical hollow at its forward end, said front section including a hollow ballistic nose and a radially thickened portion at its rearward end connected to the front end of said body section, the connected sections having at their juncture a peripheral internal cavity extending outward from the internal hollow, and a secondary projectile having the general form of a hollow cone with its base directed forwardly and having an edge flange portion fitting said peripheral cavity whereby the secondary projectile is xedly secured against axial or rotative movement prior to the detonation, said secondary projectile conforming vto and fitting against the surface of the conical hollow of the charge whereby the charge is held against movement prior to the detonation, said secondary projectile being constructed and arranged to be collapsed in diameter and expelled forwardly by detonation gases from said explosive charge, the hollow in the thickened portion having its internal wall convergent forwardly to provide a guide for-the secondary projectile during its forward movement upon the detonation, and means for detonating the charge instantaneously upon impact of the projectile with the target, said hollow front section and its connection with the body section being constructed and arranged for effecting the actuation of said firing means upon impact and for maintaining a free space forwardly of the front edge of the body section during the collapsing and expulsion of the secondary projectile.

5. A projectile comprising a strong body having an explosive charge therein of high explosion velocity, a strong intermediate member of annular form and detachably secured to said body, a hollow ballistic nose secured to the intermediate member, a secondary projectile having the gen-v eral form of a hollow metal cone with a thin wall and with its base toward the front end of the projectile and provided with an external annular flange engaged between said body and intermediate member whereby the cone is accurately maintained in position, said intermediate member having a tapered internal surface converging forwardly, and means for detonating the charge instantaneously upon impact of the projectile for effecting radial collapsing and expulsion of the secondary projectile within the space provided bysaid hollow nose.

6. A projectile comprising a hollow body section and a hollow front section, said body section hav.. ing an explosive charge therein of high explosion velocity, said front section including a hollow ballistic nose and at its rearward end an intermediate member connected to the front end of said body section, the connected sections having at their juncture a cavity extending outwardly from the internal hollow, and a secondary projectile located in front of the explosive charge and having the general lform of a hollow cone with its base directed forwardly and having an edge ange portion fitting said cavity whereby the secondary projectile is ilxedly secured against axial and rotative movement prior to the detonation, said secondary projectile being constructed and arranged to be collapsed in diameter and ex-v '7. A projectile comprising a body containing an explosive charge of high explosion velocity, a hollow cone positioned in said explosive charge with its apex toward the explosive charge and its base directed forwardly and having an apex halfangle between 18 and 30 degrees, a base fuse for firing the explosive charge within substantially one ten-thousandth of a second after initial impact, a hollow structure in front of the cone whereby to provide a hollow ballistic nose or cap thinner than the body and having a length substantially twice the caliber of the secondary projectile and effective to provide an empty space between the larger end ofthe cone and the target essentially throughout the time of detonation of the explosive charge and for causing the explosion to effect within said space a radial inward collapsing of the hollow cone into a pencil-like mass and forward propulsion of the collapsed cone at a velocity of substantially 18000 feet per second, said body and hollow structure including a portion having a forwardly convergent external taper and said ballistic nose being fitted to said external taper whereby the impact upon the target is effective to cause the ballistic nose to flare at the larger diameter of its skirt wall and move backward relative to the body while imposing a resistance eiective to cause detonation of said firing means.

HENRY HANS MOHAUPT.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,333,199 Barthelemy Mar. 9, 1920 1,105,848 Semple Aug. 4, 1914 1,825,517 Gardner Sept. 29, 1931 1,861,054 Hadeld et al May 31, 1932 FOREIGN PATENTS Number Country Date 28,030 British Dec. 13, 1911 113,685 Australia Aug. 28, 1941 OTHER REFERENCES Proceedings Royal Society, Series A, vol. 148, Jan-Feb. 1935, pp. 604-622, plates 19-23. 

